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使用AM335X芯片做ecap捕获，用到了全部三个ecap通道，ecap0用于时钟频率捕获，其中ecap1和ecap2用来捕获45HZ~55HZ方波，ecap1配置为APWM模式时，ecap2可以正常捕获到正确的周期，反之 ecap2设置为APWM模式时，ecap1也可以正常捕获到正确的周期。同时配置为ECAP_CAPTURE_MODE就都不能正常工作，求赐教。
int freq_init(void)
{
void __iomem *p_REGS;
/**************************配置时钟和设备地址映射****************************/
p_REGS = ioremap(SOC_PWMSS1_REGS, SZ_8K);
if(!p_REGS)
{
printk("%s:ioremap(%x) error\r\n", __func__, SOC_PWMSS1_REGS);
return -1;
}
g_SOC_PWMSS1_REGS = (unsigned int)p_REGS;
g_SOC_ECAP_1_REGS = g_SOC_PWMSS1_REGS + SOC_ECAP_REGS;
g_aREGS[0] = g_SOC_ECAP_1_REGS;
p_REGS = ioremap(SOC_PWMSS2_REGS, SZ_8K);
if(!p_REGS)
{
printk("%s:ioremap(%x) error\r\n", __func__, SOC_PWMSS2_REGS);
iounmap((void __iomem *)g_SOC_CONTROL_REGS);
iounmap((void __iomem *)g_SOC_PWMSS1_REGS);
return -1;
}
g_SOC_PWMSS2_REGS = (unsigned int)p_REGS;
g_SOC_ECAP_2_REGS = g_SOC_PWMSS2_REGS + SOC_ECAP_REGS;
g_aREGS[1] = g_SOC_ECAP_2_REGS;
/* Enable Clock */
ECAPClockEnable(g_SOC_PWMSS1_REGS);
while(ECAPClockEnableStatusGet(g_SOC_PWMSS1_REGS) == 0);
ECAPClockEnable(g_SOC_PWMSS2_REGS);
while(ECAPClockEnableStatusGet(g_SOC_PWMSS2_REGS) == 0);
/***************************配置两个ecap的硬件管脚*****************************/
p_REGS = ioremap(SOC_CONTROL_REGS, SZ_8K);
if(!p_REGS)
{
printk("%s:ioremap(%x) error\r\n", __func__, SOC_CONTROL_REGS);
return -1;
}
g_SOC_CONTROL_REGS = (unsigned int)p_REGS;
/* eCAP1输入管脚 AM335X_ECAP1_IN I2C0_SCL C16 */
HWREG(g_SOC_CONTROL_REGS + CONTROL_CONF_I2C0_SCL) =
(CONTROL_CONF_PULLUPSEL |CONTROL_CONF_RXACTIVE
| CONTROL_CONF_MUXMODE(3));
/* eCAP2输入管脚 eCAP2_in_PWM2_out模式 MCASP0_AHCLKR C12 */
HWREG(g_SOC_CONTROL_REGS + CONTROL_CONF_MCASP0_AHCLKR) =
(CONTROL_CONF_PULLUPSEL |CONTROL_CONF_RXACTIVE
| CONTROL_CONF_MUXMODE(4));
/****************************配置两个ecap的寄存器******************************/
/* 捕捉模式
** ECCTL2[9] CAP_APWM CAP/APWM operating mode select
** 0h = ECAP module operates in capture mode. This mode forces the
** following configuration. (a) Inhibits TSCTR resets via PRDEQ event.
** (b) Inhibits shadow loads on CAP1 and 2 registers. (c) Permits user
** to enable CAP1-4 register load. (d) ECAPn/APWMn pin operates as
** a capture input.
** 1h = ECAP module operates in APWM mode. This mode forces the
** following configuration. (a) Resets TSCTR on PRDEQ event (period
** boundary). (b) Permits shadow loading on CAP1 and 2 registers. (c)
** Disables loading of time-stamps into CAP1-4 registers. (d)
** ECAPn/APWMn pin operates as a APWM output.
*/
ECAPOperatingModeSelect(g_SOC_ECAP_1_REGS, ECAP_CAPTURE_MODE);
ECAPOperatingModeSelect(g_SOC_ECAP_2_REGS, ECAP_APWM_MODE); /* 问题就在此处 ecap2设备APWM模式时 ecap1才能正常捕获，反之亦然 */
/* 连续模式
** ECCTL2[0] CONT_ONESHT 0h = Operate in continuous mode
*/
ECAPContinousModeConfig(g_SOC_ECAP_1_REGS);
ECAPContinousModeConfig(g_SOC_ECAP_2_REGS);
/* 清除中断
** ECCLR[0:7] ECFLG&0xFF Writing a 1 clears the Int flag condition
*/
ECAPIntStatusClear(g_SOC_ECAP_1_REGS, 0xFF);
ECAPIntStatusClear(g_SOC_ECAP_2_REGS, 0xFF);
/* 这里的分频是指输入信号的分频，不是ECAP的时钟分频
** ECCTL1[9:13] PRESCALE 0h = Divide by 1 (i.e,. no prescale, by-pass the prescaler)
*/
ECAPPrescaleConfig(g_SOC_ECAP_1_REGS, 0);
ECAPPrescaleConfig(g_SOC_ECAP_2_REGS, 0);
/* enables capture loading
** ECCTL1[8] CAPLDEN 1h = Enable CAP1-4 register loads at capture event time.
*/
ECAPCaptureLoadingEnable(g_SOC_ECAP_1_REGS);
ECAPCaptureLoadingEnable(g_SOC_ECAP_2_REGS);
/* configures Capture Event polarity.上升沿捕捉 */
ECAPCapeEvtPolarityConfig(g_SOC_ECAP_1_REGS, EC_RISING_EDGE, EC_RISING_EDGE, EC_RISING_EDGE, EC_RISING_EDGE);
ECAPCapeEvtPolarityConfig(g_SOC_ECAP_2_REGS, EC_RISING_EDGE, EC_RISING_EDGE, EC_RISING_EDGE, EC_RISING_EDGE);
/* enables reset of the counters upon Capture Events. */
ECAPCaptureEvtCntrRstConfig(g_SOC_ECAP_1_REGS, EC_DELTA_MODE, EC_DELTA_MODE, EC_DELTA_MODE, EC_DELTA_MODE);
ECAPCaptureEvtCntrRstConfig(g_SOC_ECAP_2_REGS, EC_DELTA_MODE, EC_DELTA_MODE, EC_DELTA_MODE, EC_DELTA_MODE);
/* 0h = Stop after Capture Event 1 in one-shot mode. Wrap after
Capture Event 1 in continuous mode
0->0->0 CAP1 */
//ECAPStopWrapConfig(g_SOC_ECAP_1_REGS, ECAP_CAPTURE_EVENT4_STOP);
//ECAPStopWrapConfig(g_SOC_ECAP_2_REGS, ECAP_CAPTURE_EVENT1_STOP);
/* 使能中断 */
ECAPIntEnable(g_SOC_ECAP_1_REGS, ECAP_CEVT1_INT|ECAP_CEVT2_INT|ECAP_CEVT3_INT|ECAP_CEVT4_INT);
ECAPIntEnable(g_SOC_ECAP_2_REGS, ECAP_CEVT1_INT|ECAP_CEVT2_INT|ECAP_CEVT3_INT|ECAP_CEVT4_INT);
/* Disables the sync out ,sync in. TI定义的宏ECAP_SYNC_OUT_DISABLE有问题，改用EC_SYNC_OUT_DISABLE
** ECCTL2[5] SYNCI_EN 0h = Disable sync-in option
** ECCTL2[6:7] SYNCO_SEL 2h = Disable sync out signal
*/
ECAPSyncInOutSelect(g_SOC_ECAP_1_REGS, ECAP_SYNC_IN_DISABLE, EC_SYNC_OUT_DISABLE);
ECAPSyncInOutSelect(g_SOC_ECAP_2_REGS, ECAP_SYNC_IN_DISABLE, EC_SYNC_OUT_DISABLE);
/* Set Counter
** RSCTR[0:31] 0 Active 32 bit counter register that is used as the capture time-base
*/
ECAPCounterConfig(g_SOC_ECAP_1_REGS, 0);
ECAPCounterConfig(g_SOC_ECAP_2_REGS, 0);
/* 自由运行 ECCTL2[4] 1 TSCTRSTOP->TSCTR free-running 计数器停止位控制 计数器开始计数 */
ECAPCounterControl(g_SOC_ECAP_1_REGS, ECAP_COUNTER_FREE_RUNNING);
ECAPCounterControl(g_SOC_ECAP_2_REGS, ECAP_COUNTER_FREE_RUNNING);
rt_request_irq(CFG_ECAP1INT, CFG_INT_LEVEL_ECAP, freq_isr0, "ecap1", 0);
rt_request_irq(CFG_ECAP2INT, CFG_INT_LEVEL_ECAP, freq_isr1, "ecap2", 0);
return 0;
}
void freq_isr(int index)
{
unsigned int status, count = 0;
float freq;
/* 读取中断状态值 */
status = ECAPIntStatus(g_aREGS[index], 0x3F);
if(status & ECAP_CEVT1_INT)
{
count = ECAPTimeStampRead(g_aREGS[index], ECAP_CAPTURE_EVENT_1);
}
if(status & ECAP_CEVT2_INT)
{
count = ECAPTimeStampRead(g_aREGS[index], ECAP_CAPTURE_EVENT_2);
}
if(status & ECAP_CEVT3_INT)
{
count = ECAPTimeStampRead(g_aREGS[index], ECAP_CAPTURE_EVENT_3);
}
if(status & ECAP_CEVT4_INT)
{
count = ECAPTimeStampRead(g_aREGS[index], ECAP_CAPTURE_EVENT_4);
}
/* 清中断标志位 */
ECAPIntStatusClear(g_aREGS[index], 0x3F);
/* 换算成频率.不能除0 */
if(count)
{
freq = (float)ECAP_CLK_FREQ/count;
}
else
{
freq = 0;
}
//将频率范围限定在45hz到55hz。
if(freq>=44.0 && freq <= 56.0)
{
g_freqency[index] = freq;
}
}
